This application is based on Japanese Patent Applications No. 2001-203664 filed on Jul. 4, 2001 and No. 2002-93926 filed on Mar. 29, 2002, the disclosure of which is incorporated herein by reference.
The present invention relates to an air conditioning unit for a vehicle. More particularly, the present invention relates to an air conditioning unit that cools a motor of a fan by introducing a blown air into the motor.
In an air conditioning unit for a vehicle disclosed in JP-A-10-217745 (U.S. Pat. No. 6,029,469), an air intake chamber is partitioned off in an air conditioning case adjacent to a blown air passage to partially introduce a blown air into a motor. The air intake chamber has an air inlet on a side wall and communicates with the blown air passage through the air inlet. Also, the air intake chamber communicates with an inside of the motor through a motor duct. A bottom wall of the air intake chamber slopes upwardly toward the side wall having the air inlet.
For example, while a vehicle is driven under the rain, water is likely to be sucked into an air conditioning case with air by a fan. Further, the water is likely to enter an air intake chamber through an air inlet. In the above-described air conditioning unit, since the bottom wall of the air introduction chamber slopes upwardly toward the side wall having the air inlet, the water entered the air introduction chamber is stored in the air introduction chamber. Further, the water stored in the air introduction chamber is likely to be introduced into the motor with the air, thereby causing a breakdown of the motor.
The present invention is made in view of the above problem, and an object of the present invention is to provide an air conditioning unit in which entering of water into a motor is restricted.
An air conditioning unit according to the present invention has a case, a fan installed in the case and a motor for driving the fan. The case defines an air passage through which air blown by the fan is blown out to a passenger compartment. The case has a wall for defining an air introduction chamber in the case adjacent to the air passage. The air flowing in the air passage is partially introduced into the motor through the air introduction chamber. The air introduction chamber has an air inlet to allow communication between the air introduction chamber and the air passage. The wall slopes downwardly toward the air inlet and defines a lowest portion within the air introduction chamber adjacent to the air inlet.
According to this air conditioning unit, even when water enters the air introduction chamber with the air flowing in the air passage, the water is discharged to the air passage through the air inlet under the gravity. Therefore, the water is prevented from being stored in the air introduction chamber, thereby restricting the water from entering into the motor. Accordingly, corrosion of components of the motor and freezing of the motor under cold climates are suppressed.